Molecular Pathology Facility Core (MPFC) was established in 1996 as a result of the merger of the Cellular Enzymology Facility Core and the Histology Laboratory. The MPFC currently performs a wide variety of evaluations, including light- and electron-microscopy, image analysis, immunocytochemistry, in situ hybridization blotting methods (Northern, Western and Southern), and enzyme analysis. The MPFC has two facilities: the central laboratory is located in the Neurotoxicology Laboratory at Gordon Road, Kilmer Campus; and a smaller satellite facility is located in Rooms 132, 134 and 136 of the EOHSI building on Busch Campus. The specific objectives of the MPFC are: a) to make available to members of the EHS Center a facility for the preparation of high-quality histological samples in support of new and ongoing research initiatives; b) to provide expertise and consultation in the pathological assessment of histological samples, and collaboratively to assist Center members in the development and use of contemporary techniques in molecular pathology (e.g., immunoelectron microscopy, fluorescence in situ hybridization) for mechanistic studies of xenobiotic-induced injury; c) to provide large scale, iterative enzymatic analyses of samples using the FARA II centrifugal enzyme analyzer; d) to provide training for investigators, students and technical staff in various technologies and interpretation of tissue morphology; and e) to anticipate the need for emerging pathology methodologies and to establish expertise in their use. The mission and goal of the MPFC is to foster interactive research between members of the Center rather than functioning as a purely service laboratory. Modest costs are absorbed by the operating budget of the MPFC. Recurrent costs for larger studies are charged back to the user?s grants. This Core has been utilized extensively. During the past four years, 14,500 blocks have been prepared and sectioned for light microscopy, and 1,400 samples were embedded for electron microscopy. All Research Cores used the MPFC. The heaviest users were Cores I and III, with Cores II and IV using less heavily. The MPFC has been extremely active in training personnel: 15 graduate students were trained in histological techniques annually, and 8 students or postdoctorals received advanced training in the use of the FARA analyzer, EM, and molecular pathology techniques. It was also used during the summer months in conjunction with an NIH-sponsored Minority Apprenticeship Program for high school students. A variety of provisions have been implemented for future directions since the establishment of MPFC as a result of merger of two laboratories. Dr. Reuhl will retain the overall responsibility for the histology component of the Facility Core functions, while Dr. Lowndes will retain the responsibility of enzymology and immunochemistry activities. The day-to-day operation will be assumed by a technician under the direct supervision of Dr. Reuhl. Upgrading of the Core includes the following: Upgrades for the image analysis/morphology system will be sought to permit greater use of desktop publishing techniques for histological images, immunochemistry, and graphics. Using histopathological expertise present within the EHS Center, a Toxicological Pathology Users Group has been formed to review slides and discuss pathology-related issue. Future upgrading of instruments includes: 1) Software upgrading of the FARA II centrifugal analyzer which is seven years old; and 2) software upgrading of the Presage CV-6 image analysis instrument.